Troffer for fluorescent lighting fixtures readily attached to the framework of a ceiling



May 27, 1952 ATTACHED TO THE FRAMEWORK OF A CEILING 3 Sheets-Sheet 1 Filed June 11, 1948 R mm R W. :K l b E MI g I Qmw m R Q Q 3 E Q May 27, 1952 M. H. KRUGER 2,597,875

TROFFER FOR FLUORESCENT LIGHTING FIXTURES READILY ATTACHED TO THE FRAMEWORK OF A CEILING Filed June 11, 1948 3 Sheets-Sheet 2 BY be ATTORNEY May 27, 1952 H, KRUGER 2,597,875

TROF FER FOR FLUORESCENT LIGHTING FIXTURES READILY ATTACHED TO THE FRAMEWORK OF A CEILING Filed June 11, 1948 3 Sheets-Sheet 5 ATTORNEY iatented May 2 7, 1952 TROFFER FOR FLUORESCENT LIGHTING FIXTURES READILY ATTACHED TO THE FRAIWEWORK OF A CEILING Michael Henry Kruger, Malden, Mass., assignor to A. L. Smith Iron Company, Chelsea, Mass., a corporation of Massachusetts 7 Application June 11, 1948, Serial N0.'32,334

10 Claims.

This invention relates to lighting fixtures in general, and more especially to troifers for fluorescent lighting fixtures.

Among the objects of the present invention, it is aimed to provide an improved troifer for a fluorescent lighting fixture which can be readily attached to the framework of a ceiling, and readily adjusted to a predetermined level and angle.

It is still another object of the present invention to provide an improved troffer which can be installed without effort, consisting in installing successive comparatively light weight units to facilitate attachment and adjustment to a comparatively precise position at a minimum expenditure of time and with a minimum requirement of skill on the part of the attendant.

These and other features, capabilities and advantages of the invention will appear from the subjoined detail description of specific embodiments thereof illustrated in the accompanying V drawingsfln which Fi 1 is a transverse section of the lighting fixture.

Fig. 2 is a fragmental side elevation.

Fig. 3 is a section on the line 33 of Fig. 1.

Fig. 4 is a fragmental perspective showing the connection for the glass enclosure.

Fig. 5 is an exploded view showing in section several of the main units that are successively secured in place.

Fig. 6 is a fragmental side elevation of parts of a connection detail.

Fig. 7 is an exploded view, in perspective, partly broken away of parts of the connection detail shown in Fig. 6.

Fig. 8 is a fragmental transverse section showing another form of light reflecting frame.

In the embodiment shown, for connection to the I beams or T bars of ceiling constructions, and particularly for engaging and gripping the two uppermost oppositely extending webs l and 2 of a support, there are provided the gripping arms 3 and 4 formed on the extensions 5 and 6 connected by the connection "I to the lower extension 8 of the main bracket 9. The inwardly extending arm [0 of the bracket 9 has formed at the end thereof the upwardly inclined and outwardly extending flange H with enlarged openings provided in the end portion of the arm [0 and flange ll constituting overlapping bent portions registering with one another to enable the screw l2 freely to extend therethrough. The flange I I oooperates with the arm l0 to encapture or anchor the nut l3 screw threadedly connected to the screw [2, the openings in the flange II and arm it being large enough as aforesaid freely to permit the screw 12 to pass therethrough. The screw it in the present instance, see Fig. 5, extends through the auxiliary bracket I4 which includes an inwardly extending lower web or supporting flange or bent portion [5, a second web it spaced from, and substantially parallel to, the web l5 by the intermediate web IT, and a third web l8 spaced from, and substantially parallel to, the webs i5 and it by the elongated web portion E9. The webs l5, I6 and I8 constituting overlapping bent portions are provided with openings registering with one another freely or hingedly to receive the threaded shank of the screw I2 and anchor the same freely to move therein, the opening in the web i5 being smaller than the head 20 of the screw l2 so that the web IE will form an abutment for it. Between the web It and arm ID of the bracket 9, there is interposed a coil spring 2i encircling the threaded shank of the screw i2 so that when the screw [2 is turned in the nut It, the lower Webs l5 and It may be adjusted upward or downward, that is, nearer or farther from the arm It against the tension of the spring 2i. From the foregoing it will thus be seen that the auxiliary bracket M is freely movable or rockable relative to the bracket 9 and that any lighting fixture elements supported on the inner extension or ledge 22 of the web [5 may be raised or lowered to a predetermined precise location by the manipulation of the screw I2 with relation to the nut I3 and against the tension of the spring 2| so that at least in an upward direction the lighting fixture will be yieldable to facilitate proper adjustment and handling of the associated parts while assembling them.

After the required number of brackets 9 are positioned on the supporting beams, including the webs and 2, then the same may be slidably moved along the webs I and 2 into position to receive the trough-shaped housing 23 which in the present instance has a roof portion 24 extending the length of the lighting fixture, conventional lengths being four feet and eight feet, with the proviso that for a four foot length only two pairs of brackets 9 are preferred, two brackets on each side, and that for an eight foot length, three pairs of brackets 9 are generally preferred, three brackets'on each side.

In the present instance, the housing 23 has side wall members 25 including the short shoulder portions 26 adjacent the roof portion 2t inter mediate the roof portion 24 and the inclined portions 21, and the inclined portions 2'! intermedithe conventional lamp sockets and connections:

The, end. brackets, ac, see

for fluorescent lamps. Fig. 2, preferably have websor flangesfiiextending outwardly in a longitudinaldirection,.thatis,,

toward the ends of the housing 23, and downwardly extending flanges 32zattheir sideslsecureds;

to the Vertical wall portions28 'of the housing fif;

In the act of assembling, the housing 231s pressed upwardly between pairs of, auxiliarybrackets l4, in which case the inclined wall portions 21 of the housing 23 will cam the brackets I4 outwardly to engage the vertical wall portions 28' and here due to thenormally free movement of'the brackets i4 relative to thebrackets-S, the extensions 22 are deflected outwardly until they clearthe lower ends of thewall portions-28 where the extensions 22 may be pressed inwardly, to receive the flanges 29; Thereupon the screws l2 may be turned to;aline the'sides-ofthe housing 23, as an instance, or to assume whatever other positionitisdesired. With the auxiliary brackets 14 and associated-screws l2 andspringszl, it will be seenthat in the course of assembling one Or the other'side or both of the housing 23 may be pressed upwardly against the tension of the springs 2l without liberating the housing 23,,as av result of. which, the danger of dropping the housing 23, in the act of assembling the lighting fixture, is reduced-to a minimum.

After the housing 23 has been properly secured in place, the-main reflector 33 may be secured in place. The reflector 33 consists essentially of two downwardly extending and outwardly flaring wall members 34 having at their upper ends the shoulder forming bead 35, substantially V-shaped in cross-section, the upper web 36 of which forms the supporting ledge for the intermediate strap or bridge-31w-hichin the present instance has alaterally extending slot 38 to re.- ceive the.- wingnut 39 and elongated abutment 40 formed on the rod 4|, screw threadedly connected at its upper end to the roof. portion24, see Figs. 1, 2 and 5. In the actof assembling, it ishere only necessary to raise thereflector 33 where the slot 38 registers with the abutment 4D and wing nut 39, permit the same to pass through the slot 38and then turn the wing nut 39 sufficiently so that the strap willbe anchoredbyv the abutment 4i]. Thereupon the'spring lock fastener screws 6.1 may be turned into place, connecting the web or flange 42 to the flange3l, the flange 42 .extending inwardly from the end wall mem: bers 43 which are connected to the wall members 34 of the reflector 33'. Thereupon, preferably the screws [.2 may be turned to finally aline the sides of the housing 23with the reflector 33, inturn to aline with the ceiling or to assume Whatever other position it is desired. Before inserting the lamps (not shown) in place, the lower end of the housing 23 is closed by a coverplate, such as the plate 51'. This plate preferably has a longitudinally extending slot 58, Fig. l. quently, after the reflector 33 has been secured in place, preferably the Wing nuti 39and abutment 40 are turned to extend longitudinally and in position to aline with the opening 58 and clear it when the plate 51 is raised into proper Conseposition, when the wing nut 39 is again turned, preferably at right angles to its second position so that now the abutment 40 will engage the lower face of the plate 51 and anchor it in position.

In'some instances, the .spacebetween,the lower edges of thewalls-34 is closed by alightpdeflecting member, such for instance as a sheet or plate 44 of translucent glass. The plate 44 in the present instance is anchored in a frame having end pieces 45 connected to the upwardly extending;flanges,45;ofthe side pieces 41 and 48. The side piece 48* includes a horizontally extending supportingflangeAQzextending at right angles to the flange 46-. and connected to the same by the shoulder forming: portion 50. The flange 46 of thesideflpieoeifl, is connected to the horizontally extending flange portion 5| by the shoulder forming; portion 52 which is recessed to receive portions of the strips 53 secured at their upper ends tothe inner faces of said wallmembers-34 and 1 the lower ends of which form vjournalswith the side pieces 4'! to receive the pivot pin-5iv Theshoulder forming portions 50. have recesses therein toreceive the projections 55, formed on the-straps.idsecuredto, the inner; face ,ofone of the walls 3.4 as shown\in.Fig. 1.. The glass enclosure. plate liii iszthus pivotally. mounted by, the pin 56 to the lower edge of one side wall. 3.4 and supported in-horizontal position by thecooperation of the projections .551with therecesses in the shoulder. forming portionsiill of the side pieces 48.

The .sheetmetal strips.53 constitutethe spring supports for the hinge, formedib'y the stripsp53. and sidepieces 4.1' with the.-.pivot pin-54l In place of the glass plate, 44, see-Fig. 8, the egg cratelouverframe 6 I may be provided, which preferably, as showninmy co-pending applicati-on for PatentSer. N0. 32 B35 filed simultaneously herewith which ,issuedJuly, 10,195]; as PatentNo. 2,559,640, is provided with hook-shaped'formations 62; in. vertically extending cross .plates;63 to receive the supporting bars at the free ends of the arcuate members 64 pivotally connected at their-upper ends to the brackets 35 secured to, the, inner faces of the downwardly extending outwardly flaring: walls 66*ofthereflector-B'li It is obvious that various changes andmodifications may be made. to' the details of construction without departing from the; general spirit of the inventionas set forthin theappended claims:

Iclaim:

1. The combination of brackets having-upwardly extending arms extending inwardly toward one another, the inner ends of said arms being free, auxiliary bracketshavingoutwardly extending bent portions at" their upper; ends" extending a over the inner free; endsofsaid'arms, said-auxiliary brackets'having'inwardly extendingsupporting bentportions at their lowerends, a trofier housing mounted" on, said" supporting bent portions, and means connecting the outwardly-extending. bent portions to the, free endsof said arms to enablemovement offsaidiauxiliary bracke ets relative to saidarms.

2. The combination. as-set forth in, claim 1 characterizedby the freev ends of said armshaving faces. inclining upwardly in an inward. di? rection, the connectingnneans including nuts on springpressed screws, cooperating withsaid'faces for resiliently urgingthelower ends of said'auxiliary brackets inward into engagement with said troffer housing, the connecting means being yieldable to enable the auxiliary brackets to be deflected outwardly by said housing when elevating the same into supporting position on said webs.

3. The combination as set forth in claim 1 in which the free ends of said arms have faces inclining upward in an inward direction, and the connecting means include nuts on spring pressed screws connected to the inwardly and outwardly extending bent portions of the auxiliary brackets and to the free ends of said arms to facilitate adjusting the position of said auxiliary brackets and to cooperate with said faces resiliently to urge the lower ends of said auxiliary brackets inward into engagement with said troifer housing, the connecting means being yieldable to enable the auxiliary brackets to be deflected outwardly by said housing when elevating the same into supporting position on said bent portions.

4. The combination as set forth in claim 1 characterized by said housing having inclined faces, and the connecting means including springs for resiliently urging the lower ends of said auxiliary brackets inwardly into engagement with the inclined faces of said housing when said housing is elevated in the process of assembling thereby in turn to deflect said auxiliary brackets outwardly until they clear the lower edges of said housing and then snap into supporting engagement with the lower edges of said housing.

5. The combination as set forth in claim 1 in which lamp sockets extend downwardly from said troifer housing and a reflector is connected to said troffer housing and extends down outside of the lamps connected to said lamp sockets.

6. The combination as set forth in claim 5 in which the reflector has a bridge, and the cover for said housing and said bridge has elongated slots extending at angles to one another but intersecting a common axis, and means for connecting the cover for said housing and said bridge to said housing including a rod screw threadedly connected to said housing and having an elongated abutment and wing nut movable through the slots in said bridge and cover one at a time and anchoring the bridge and cover to said housing by turning said abutment and wing nut out of registration with the slot in said bridge after passing through the same, thereupon to support the reflector, and thereupon registering with and passing through the slot in said cover and after passing through the same being turned out of registration with said latter slot thereupon to anchor said cover in position.

7. The combination of main brackets having upwardly extending arms extending inwardly toward one another, the inner ends of said arms being free, auxiliary brackets having inwardly extending supporting bent portions, a troffer housing including downwardly extending side walls mounted on said supporting bent portions, each of said main brackets having two overlapping bent portions at their inner free ends, each of said auxiliary brackets having two bent portions overlapping its inwardly extending supporting bent portion, the uppermost bent portion of each auxiliary bracket disposed above the two bent portions of an associated main bracket and the lower two bent portions of each auxiliary bracket disposed below the two bent portions of its associated main bracket, there being openings in said five overlapping bent portions, a screw extending through said five bent portions with its head abutting against the lower face of the lowermost bent portion of its associated auxiliary bracket, a nut screw threadedly connected to each screw and interposed between the two bent portions of a main bracket, and a coil spring on each screw interposed between the lowermost bent portion of a main bracket and the next lowermost bent portion of its associated auxiliary bracket.

8. The combination of brackets having opposing jaws slidably to grip the opposite edges of a support, said brackets having upwardly extending arms extending inwardly toward one another, the inner ends of said arms being free, auxiliary brackets having outwardly extending bent portions at their upper ends extending over the inner free ends of said arms, said auxiliary brackets having inwardly extending supporting bent portions at their lower ends, a troffer housing including downwardly extending side walls mounted on said supporting bent portions of said auxiliary brackets, a reflector connected to and extending downwardly from said housing, a cover for the lower end of said housing, and means connecting the outwardly extending bent portions of said auxiliary brackets to the free ends of said arms to enable movement of said auxiliary brackets relative to said arms.

9. The combination of brackets having upwardly extending arms extending inwardly toward one another, the inner ends of said arms being free, auxiliary brackets having inwardly extending supporting ledges at their lower ends, a trofier housing mounted on said supporting ledges, and hinge means connecting these auxiliary brackets to the free ends of said arms to enable movement of said auxiliary brackets relative to said arms.

10. The combination of brackets having upwardly extending arms extending inwardly toward one another, the lower ends of the upwardly extending arms formed to receive supporting means and the inner ends of said arms being free, auxiliary brackets hinged to the free ends of said arms and having inwardly extending supporting ledges at their lower ends, a troffer housing mounted on said supporting ledges, and adjustable means to raise or lower the auxiliary bracket relative to said arms.

MICHAEL HENRY KRUGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,028,453 Hoffman Jan. 21, 1936 2,270,814 Scribner Jan. 20, 1942 2,305,015 Langer Dec. 15, 1942 2,335,736 Campen Nov. 30, 1943 2,365,614 Winkler Dec. 19, 1944 2,463,057 Runge Mar, 1, 1949 

